package it.getta.vicinometro.utils;

import it.getta.vicinometro.R;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;

public class ImageLoader {
    
    private MemoryCache memoryCache=new MemoryCache();
    private FileCache mFileCache;
    private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
    ExecutorService executorService; 
    
    public ImageLoader(Context context, FileCache fileCache){
        mFileCache = fileCache;
        executorService=Executors.newFixedThreadPool(5);
    }
    
    final int stub_id=R.drawable.ic_launcher;
    
    public void DisplayImage(String url, ImageView imageView)
    {
        imageViews.put(imageView, url);
        Bitmap bitmap=memoryCache.get(url);
        if(bitmap!=null) {
//        	imageView.setLayoutParams(new Gallery.LayoutParams(300, Utils.convertDensityPixel(110, mContext)));
        	imageView.setImageBitmap(bitmap);
        }
        else
        {
            queuePhoto(url, imageView);
            if (url.endsWith("_t.jpg")) {
				imageView.setImageResource(stub_id);
			}
        }
    }
        
    private void queuePhoto(String url, ImageView imageView)
    {
        PhotoToLoad p=new PhotoToLoad(url, imageView);
        executorService.submit(new PhotosLoader(p));
    }
    
    private Bitmap getBitmap(String url) 
    {
    	Utils.hardLong("FILECACHE PATH: " + url);
        File f = mFileCache.getFile(url);
        
        //from SD cache
        Bitmap b = decodeFile(f);
        if(b!=null)
            return b;
        
        //from web
        try {
            Bitmap bitmap=null;
            URL imageUrl = new URL(url);
            HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
            conn.setConnectTimeout(30000);
            conn.setReadTimeout(30000);
            conn.setInstanceFollowRedirects(true);
            InputStream is=conn.getInputStream();
            OutputStream os = new FileOutputStream(f);
            Utils.CopyStream(is, os);
            os.close();
            bitmap = decodeFile(f);
            return bitmap;
        } catch (Exception ex){
           ex.printStackTrace();
           return null;
        }
    }

    //decodes image and scales it to reduce memory consumption
	private Bitmap decodeFile(File f) {
		
		if(f.getAbsolutePath().endsWith("_b.jpg") || f.getAbsolutePath().endsWith("_t.jpg")) {
			try {
				return BitmapFactory.decodeStream(new FileInputStream(f));
			} catch (FileNotFoundException e) {
				return null;
			}
		} else {
			try {
				// decode image size 
				BitmapFactory.Options o = new BitmapFactory.Options();
				o.inJustDecodeBounds = true;
				BitmapFactory.decodeStream(new FileInputStream(f), null, o);

				// Find the correct scale value. It should be the power of 2.
				final int REQUIRED_SIZE = 70;
				int width_tmp = o.outWidth, height_tmp = o.outHeight;
				int scale = 1;
				while (true) {
					if (width_tmp / 2 < REQUIRED_SIZE
							|| height_tmp / 2 < REQUIRED_SIZE)
						break;
					width_tmp /= 2;
					height_tmp /= 2;
					scale *= 2;
				}

				// decode with inSampleSize
				BitmapFactory.Options o2 = new BitmapFactory.Options();
				o2.inSampleSize = scale;
				return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
			} catch (FileNotFoundException e) {
				return null;
			}
		}
		
	}
    
    //Task for the queue
    private class PhotoToLoad
    {
        public String url;
        public ImageView imageView;
        public PhotoToLoad(String u, ImageView i){
            url=u; 
            imageView=i;
        }
    }
    
    class PhotosLoader implements Runnable {
        PhotoToLoad photoToLoad;
        PhotosLoader(PhotoToLoad photoToLoad){
            this.photoToLoad=photoToLoad;
        }
        
        @Override
        public void run() {
            if(imageViewReused(photoToLoad))
                return;
            Bitmap bmp=getBitmap(photoToLoad.url);
            memoryCache.put(photoToLoad.url, bmp);
            if(imageViewReused(photoToLoad))
                return;
            BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad);
            Activity a=(Activity)photoToLoad.imageView.getContext();
            a.runOnUiThread(bd);
        }
    }
    
    boolean imageViewReused(PhotoToLoad photoToLoad){
        String tag=imageViews.get(photoToLoad.imageView);
        if(tag==null || !tag.equals(photoToLoad.url))
            return true;
        return false;
    }
    
    //Used to display bitmap in the UI thread
    class BitmapDisplayer implements Runnable
    {
        Bitmap bitmap;
        PhotoToLoad photoToLoad;
        public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;}
        public void run()
        {
            if(imageViewReused(photoToLoad))
                return;
            if(bitmap!=null)
                photoToLoad.imageView.setImageBitmap(bitmap);
            else
                photoToLoad.imageView.setImageResource(stub_id);
        }
    }

    public void clearCache() {
        memoryCache.clear();
        mFileCache.clear();
    }

}
